I understand that the Tetragrammaton is the G‑d's true name. So why is G‑d also referred to in the Torah as "Elokim"? Isn't one name enough?


When Abraham started off, people understood that there is one original G‑d who is the essence of being. This is what we refer to with the four-letter name, the Tetragrammaton, whose code name in Kabbalah is "Havaya." That name can only be written in singular form. In fact, it is basically a conjugation of the verb "to be."

They knew of this concept of Havaya, but they considered it far too lofty an idea, seemingly inaccessible and irrelevant to their lives. Instead, they connected to the many forces of nature. They called these "Elohim"—meaning, "mighty forces."

Abraham came along and said, "You guys got it all wrong. Havaya is Elohim! It's all one! He is the essence of being and He is all the forces of nature in one big package!"

That's why, as the Biblical commentator Baal HaTurim points out, the Hebrew letters in the name Elohim have the same gematria (numerical value) as "haTeva"—which means the natural order.

For more on the relation of these two names of G‑d, see Shaar HaYichud V'ha-Emunah by Rabbi Schneur Zalman of Liadi. You can find that here.